quak backup no longer refreshes its library on a timer (closes #183)

The backup opened its library with the default 3-second refresh interval,
so for its whole run it asked the server for changes every few seconds,
and each refresh started another ML data pass. It now opens it with
refreshIntervalSeconds: Infinity. The library takes Infinity as no
background timer, since setTimeout would turn it into 1 ms. A refresh
interval of 3600, as the read commands use, would still refresh once an
hour in a backup that runs for hours.

Model: opus-5-5

src/cli-commands.ts

@@ -427,10 +427,13 @@ export const backupCommand = async (
     try {
         // The precache is off: the backup fetches what it needs, and must not
         // also fill the cache with every thumbnail and the recent originals.
+        // No refresh starts on a timer: the backup lists its files once, from
+        // the refresh it waits for, and can run for hours.
         const lib = await Library.open({
             client,
             downloadDirectory: dir,
             cacheDirectory: ctx.cacheDir,
+            refreshIntervalSeconds: Infinity,
             precacheThumbnails: false,
             precacheOriginals: false,
         });